Double-adjustable drive-chain idler



June 7,1927. 1,631,258

H. G. GAY

DOUBLE ADJUSTABLE DRIVE CHAIN IDLER Filed Oct. 18, 1926lllllllllllllllllllll lllllllllllllllll IN VEN TOR.

ATTORNEY Patented June 7, 1927.

U T TATES; PATENT omen.

HENRY GRADY ,GAY, or MANKINS, TEXAS.

DOUBLE-ADJUSTABLE DRIVE- HAIN IDLER. I

Application filed October 18, 1926. Serial No. 142,477.

. This inventionrelates to belt tighteners and it refers moreparticularly to an adjustable rotary drive chain idler, especiallydesigned for the drive "chain of a rotary well drilling outfit, and itsprincipal object resides in the provision of an apparatus'of thecharacter designated which maybe placed beneath the drive chain and iscapable of retaining a positive position with respect to the chain whenadjusted according to the speed of the chain. I

Otherobjects,'inadditionto those mentioned, will become obvious in theconstrue tion of the invention and its assembly of parts, and will berevealed as the description proceeds, taken in connection with the ac?companying drawings, wherein:

' Figure '1 is a side elevational view of an apparatus constructedaccording to'the in- Vention in operative position.

Figure 2' is likewise aside elevational view. [j I Figure 3 is an endelevation of the appara-tus," and l Figure 4: is a cross-sectional Viewon lines 4+4 of Figure 2.

Continuing now more in detail with the drawing, it may be stated thatsome disadvantage has been encountered by constant slapping broughtabout by the slackness of the rotary drive chain, such condition oftenresulting in kinking the chain, probably breaking the latter as aconsequence. This not only is expensive, but is also troublesome to theoperator. For proper performance, under varying conditions, some slackmust be allowed in the chain. It is to take care of this slackness thatthe invention has been devised.

The invention primarily consists of base runners, consisting of angle orchannel iron, having pivoted to one end in the manner shown at a asliding sprocket carriage track 2. As illustrated in Figure 4, thesliding sprocket carriage 3 is grooved at either side so as to receivethe inwardly turned flanges 4 formed upon the track 2, in such a manneras to permit free endwise movement of the carriage. In order toaccomplish this endwise movement, a gearedlift 5 is mounted at theopposite end of the base 1 so as to be capable of co-operating with thecarriage track 2 in movement, that is, to remain at a all times at rightangles with the track, irrespective of the angle assumed by the latter.A gear6 is carried intermediate the track 2 andis so disposed asto'engage both,

the teeth on the bar 5 and those 7 on the underside of the carriage 3.Therefore, upon rotation of the gear by operating the crank 8, forwardor backward sliding of the carnage 3 is in accordance with therespective raising and lowering of the carriage 3 and its track 2, whichhas been mentioned as being pivoted at a tothe base 1. Apertures 9,alined in spaced relationship in the lifts 5 are adapted to registerwith the aperture 10 in the carriage track 2, and through which asuitable pin is passed to hold the track in anyposit-io'n' desired. I 1

i A roller or-other equivalent means 11 "is carried between the tracks 2against which the geared lifts 5 rest, to prevent their release from thegear 6, and a clamp 12 is mounted over the carriage 3 toguideftheforward end of the latter, since this end,

which is supplied with the teeth 7 is not engaged by the flanges l ofthe track 2, and being narrower so as to conveniently pass b-etween'thetwo upright bars comprising the lift 5/ A sprocket13 is mounted inbearings 14: near the end of the carriage 3 opposite the teeth 7 in anaperture formed therefor.

Accordingly and in operation, the base members 1 are securely fastenedto the derrick floor, assuming that the invention is so used, and inalinementwith the rotary drive chain not shown but under which thesprocket 13 is positioned.

Upon rotating the crank shaft 8, the track 2 is elevated, simultaneouslywith the sliding movement of the carriage 3 in the direction of thepivot point a of the track, this being brought about by the dualfunction of the gear 6 through its engagement with the teeth 7 beneaththe carriage 3' and geared lift 5. The sprocket 13 thus changes itsposition with respect to the chain, being moved upward and forward tothereby engage the chain, urging the same upward and reducing the slackand consequent slapping thereof.

Manifestly, the construction shown is capable of considerablemodification, and such modification as is in keeping with the appendedclaims, is considered within the spirit of the invention.

I claim:

1. In an adjustable rotary drive chain idler, a base, a carriage trackpivoted at one end to the base; a geared carriage capable of endwisemovement on the track, and carrying an idle sprocket; a geared liftpivoted to the other end of said base and arranged normally in uprightposition; means to dually engage the gears of said carriage and lift toelevate the carriage track simultaneous with sliding movement of saidcarriage.

2. In an adjustable rotary drive chain idler a base member; a carriagetrack PlVOlm ally carried by the base member; a carriage slidablycarried by the track and having toothed under surface near one end; asprocket carried by the carriage; a geared lift arranged adjacent thetoothed portion of 3 the carriage and means on the track to duallyengage the lift and teeth of said carriage to elevate the track and movethe carriage thereon.

3. In an adjustable drive chain idler, a carriage track supporting aslidable carriage having a toothed under surface, an idle sprocketcarried by said latter element;

7 means arranged at one end having a toothed surface; and a gearengaging said toothed surfaces jointly to elevate one end of said tracksimultaneous with the consequent sliding movement of said carriage.

4. In an adjustable drive chain idler, a carriage track having one endpivotally held; a geared lift arranged adjacent the other end of saidtrack; a gear carried by said track and engaging the gears of said lift;a slidable carriage also carried by said track having toothed portionengaged by said ably supported on said track carrying an idle sprocketand having a toothed surface also engaged by said gear, and means torotate said gear to cause upward movement of said track with slidingmovement of said carriage.

6. In an apparatus of the character described, a stationary base member;a carriage track pivotally held at one end to one end of said basemember; a geared upright pivotally held at the other end of saidbasemember; .a gear carried by said track and 00.- operating with saidupright to raise the track when rotated; a carriage having restrictedsliding motion on saidtrackprovided with a toothed surface alsoeo-operating with said gear; an idle sprocket carried by said carriage,and means to rotate said gear to cause co-operative movement of saidtrack and carriage.

In testimony whereof I affix my signature.

HENRYGBADY GAY.

